I have just acquired some Edison radios from 1929 and 1930. I have a C-4, an R-5, and an R-6 from 1930. They are not Super-het radios, but TRF types called Neutradyne I think. Can anyone tell me what would be different on these Edisons from a 1940 era radio that I should look for. I think the 1930 radios don't have electrolytic caps. Is that true? And as I look at the bottom, I don't see all the wires, resistors, and caps that you see in a 1940 radio. I guess most of that is in the boxes?

What's the difference between a 1929 radio and a 1941 era?

about ten years

Gee, this is such a general wide-open field question.

The difference between a 1929 radio and a 1941 radio?
Smaller, lighter, more refined circuitry. Superheterodyne was long since the norm by 41. Most have shortwave with a few sporting the new FM band. Usually, they have much better fidelity and power output.

1929 radios were bulky and heavy by comparison. some had electrolytics by then. The large can Mershon wet electrolytic had been around a couple years by then, but many used paper filters with large heavy chokes to compensate for the low capacity filters. usually AM Broadcast band only and very few had AVC (Automatic Volume Control).

Thats all I can throw out off the top of my head.

-Steve

1941:
More advanced circuitry (including superhet)
smaller tubes
different tube configurations
better parts available
different cabinet styles---eg more plastic and less wood
different dial layouts--added pushbuttons
PM speakers coming in?

Other than that, not much......

You won't risk a hernia lifting a 1941 radio and the 41's are far, far, superior in performance.

Pete

A big improvement in fidelity also.

Carl

You might risk a hernia if you try lifting a 1941 Capehart!

-Steve

Probably also they cost more of your months pay to acquire in 1929, than in 41. I bet you got alot better performance for less money by 41. Compare schematics, if you can find some. They had more low gain triodes versus higher gain pentodes in 29 so you needed more stages, I think. I expect the service lifetime of the 41 radios was longer than the 29s. Got more use out of them.

TOPIC CHECK....

The OP is asking about Edison radios, not radios in general. That would be quite a daunting question.

Nick, that is not what the subject line indicates, and the question could be interpreted either way.

Add to that, there were no Edison brand radios in 1941, so it is a moot point.

-Steve

Jumped the gun...

Actually, I was more interested in how would I approach restoring an Edison radio as opposed to learning about a 40s radio. What are the big differences in restoring the radio. Would I start by pulling out the caps and replacing them? But I guess very few of you have owned an Edison due to their rarity.

around the 30s early radios power supply filter capacitors were paper and foil wrapped and sealed in pitch in a can. very robust when new but a real challenge to replace the now failed component inside. it is tricky and delicate because sometimes the transformers are in there too. I will let others say how the best ways might be to break into the tar box. probably better methods than mine

I don't know if I'd break into the tar box. I have a 1929 Erla 224-AC like that. Fortunately, the transformer and chokes are located in separate boxes so it was easy for me to just disconnect them and install electrolytics directly to the tube and speaker sockets.

Several years ago I tried breaking into one of those boxes on an RCA. They used heavy duty metal tabs to anchor the box to the chassis. It was a major league you-know-what just to unbend those tabs. I'm now a coward with regards to tampering with tar boxes, so I say this: If you can get away with using tie straps or direct connections to connect new caps under the chassis, I'd say do that. If there is a filter choke incorporated in one of the boxes, I'd disconnect everything but the choke and connect new caps under the chassis.

But that's just me.

BTW, don't trust tar box caps even if they check good. I made that mistake with the Erla. They checked good so I ran the set with them still connected for a couple of weeks. Then the set started to sound distorted. When I checked them again a lot of the tar had melted and leaked out through the vent holes.

I don't want to sound flippant but there's a huge difference. The 1920's radios were variously detector/audio only, TRF, neutradyne, reflex and other innovative work-arounds to get gain and stability from early triode tubes. Most were battery operated. Virtually none were superhets as, IIRC, the Armstrong patent had just come out and scared everyone off. By the late-1930's they were virtually all superhets with better tubes. By 1938, or so, the 5 tube AC superhet and the AA5 were as good as standard for the mass market.
BTW, I just acquired three vintage radio books on eBay, all by Moyer and Wostrel. They are:
"Radio Receiving Tubes" (1929)
"Practical Radio" (1928), and
"Practical Radio Construction and Repairing" (1930)
Having devoured these cover to cover I can say that they are great history and fascinating reading. Right up to the (then) latest technology of the day they are detailed and informative but, with 20/20 hind-sight, I kept thinking "yes, but why not do this?!" Quite unfair, of course!
For example, a 60 KHz IF (for the few superhets) was lauded as you could amplify it easily with a triode tube but, as we know, image interference was endemic (but few stations.) They could not peak the IF, as we do at 455 KHz, as it took out the audio sidebands! We are standing on the shoulders of giants!
Cheers,
Roger

One big difference was by the early forties built-in loop antennas were becoming standard: in 1929 you still had to string up an outdoor antenna.

interesting all this came from different ways of looking at the Edison Effect. curious minds developing what we have today from what would now be considered a simple event. you need a spark to light a fire